1. Field of the Invention
The present invention relates generally to the field of graphical-code reading computer systems. More specifically, the present invention relates to systems and methods for pixel gain compensation in machine-readable graphical codes.
2. Description of Related Background Art
Computer technology has entered many areas to simplify manual tasks and to make information more readily available. Most people use several computer programs every day that greatly simplify their work day. In addition, through the use of a computer, vast amounts of information are readily available. Computer software and electronic information sources are typically found on storage media or storage devices such as hard drives, CD-ROMs, DVD-ROMs, etc., on a local computer, on a local computer network or a global computer network, such as the Internet.
Computer programs can be used for many purposes including assisting a person in performing his or her job. For example, word processors help computer users prepare documents, spreadsheet programs help users perform accounting functions and numerical analysis, diagnostic programs assist users in diagnosing problems, etc. There are a number of programs available to help users with various needs that they may have. Typically, computer programs operate upon source data in order to help a user. Thus, the source data needs to be input into the computer program.
One way to input source data into a computer program involves the use of machine-readable graphical codes, such as bar codes, matrix codes, etc. Graphical codes may be inserted into printable documents or printed on labels that can be affixed to objects. The use of these graphical codes may greatly simplify the actions required of a user to access relevant information.
Graphical codes are typically printed by a printing device on a printing surface, such as paper. The smallest unit within a graphical code is a pixel. Each pixel within the graphical code may increase in size when printed. This occurrence is referred to herein as pixel gain. Pixel gain may be due to the fact that some printing surfaces readily absorb the ink used by the printing device. This is often referred to as ink bleeding. Many factors affect pixel gain, including the printing device, the type of ink used, the type of printing surface used, etc.
Unfortunately, pixel gain may cause graphical codes to become unreadable. For example, a graphical code typically includes a white region adjacent to a non-white region. The width of the non-white region, and/or the distance between a first non-white region and a second non-white region, may contain information that may be converted into useable data by a graphical code reading device. If the sizes of the white and non-white regions become distorted because of pixel gain, it may become difficult for the graphical code reading device to accurately read the graphical code. Accordingly, benefits may be realized if means were provided to reduce the effects of pixel gain in machine-readable graphical codes.